CHAPTER IX.
The Skin and its Diseases—Gangrenous Erysipelas—Lice—Leprosy—Mange—Measles—Desquamation of the Skin.
THE SKIN.
The skin of the hog, like that of most other animals, is composed of three separate parts or layers. The first or exterior of these is the cuticle or scarf skin, which covers the whole surface of the body and protects the more sensitive parts from the injuries which might result to them from immediate contact with external agents. It is a thin, tough, callous texture, perforated with innumerable holes or pores, through which pass the hairs and bristles, and whence exude those transpirations by means of which the body throws off all vapors injurious to the system. Chemical analysis has proved it to be chiefly composed of gelatine, and consequently insoluble in water of common temperature. This layer is considerably tougher and denser in the hog and other of the pachydermata than it is in the horse, ox, and most of our domesticated animals.
Beneath this is the rete mucosum, a soft expansion of tissue which overspreads, and can with difficulty be separated from the layer below it. Its purpose appears to be to protect the terminations of the blood-vessels and nerves of the skin, which it in a manner envelops or covers. This layer determines the color of the body and of the hair.
The third and undermost part is the cutis vera or true skin, an elastic texture composed of innumerable minute fibres crossing each other in all directions, fitting closely to every part of the frame, yielding by its elasticity to all the motions of the body, and interposing its dense, firm structure between the more vital parts of the system and external injuries. Innumerable blood-vessels and nerves pass through it, and appear upon its surface in the form of papillæ; it is in fact far more sensitive than the muscles or flesh.
The skin varies in density in different breeds of swine. In some of the large, old breeds it is thick, coarse, tough, and almost as impenetrable, in comparison, as the hide of a rhinoceros; while in many of our smaller breeds, and particularly in those which have a considerable admixture of Asiatic blood, and in the Chinese pigs themselves, it is soft, fine, and delicate, and bears no slight degree of resemblance to the skin of the human being. It is not to be wondered at, that a structure so delicately organised as the one we have been describing should be subject to disease. In the hog it is peculiarly so; many of the most serious maladies to which he is subject, have their seat in the skin: it were a point well worthy of study to inquire into the reason of this fact, but as the present work is devoted to practice rather than theory, we must leave it to abler hands, and pass onwards to a consideration of some of the most prevalent diseases of the skin in swine.
GANGRENOUS ERYSIPELAS.
This disease, which is frequently spoken of by the ancient writers, as prevailing to a greater or less extent, and often almost as an epidemic among sheep and swine, is now of rare occurrence. Poulet thus describes the symptoms:—
"The first of these, which last some five or six days, are uneasiness, inquietude, depression, loss of appetite, and inertness. About the seventh or eighth day these gradually increase in intensity; the limbs totter, the body is alternately hot and cold, the ears droop and are cold, the head appears heavy, the tongue is discolored, the breath fetid, a thick mucus flows from the nostrils, and the whole of the skin becomes tinged with an erysipelatous redness, which is most evident under the belly; the animal utters almost incessant screams of pain. This inflammatory state of the integuments rapidly merges into decided gangrene, and the whole of the diseased surface becomes of a livid blue or violet hue. The skin is first covered with blisters containing a thin reddish watery fluid; and as these break, the gangrenous, dark colored scabs are formed. The disease is, however, by no means of so fatal a character in swine, as it is in sheep, probably from the former being the stronger animals. A little blood should be taken from the ears, once at any rate, and the bleeding should be repeated if it appears at all necessary. A dose or two of Epsom salts, cooling drinks slightly acidulated, and strict attention to diet and cleanliness, are generally all that will be requisite. Should the skin appear to be very irritable, a little sweet oil may be rubbed over it, or some sulphur made into a kind of ointment with sweet oil or palm oil; but local applications are not generally requisite."
Exposure to great heat or cold, or any sudden transition from one extreme of temperature to another, are supposed by some authors to be the causes of this disease; while others, and we think with justice, attribute it to unwholesome or putrid food, and to general inattention and neglect.
LICE.
Pigs, when allowed to wallow in the mire, and to dwell in filthy styes, are very apt to engender these disgusting vermin, which eat into the skin and render it scabby and ulcerated, and by the irritation they keep up, worry and fatigue the animals, and effectually prevent them from thriving. Eric Viborg states that these vermin sometimes burrow their way into the flesh and come out through the eyes, nostrils, or mouth, or have even been known to be voided in the urine.
The first step to be taken towards effecting a cure is thoroughly to cleanse the skin from every particle of dirt, and to clean out and whitewash the styes and put in fresh dry litter.
Mercurial ointment, turpentine, or tobacco-water, are the most efficient agents in the destruction of these unwelcome parasites. A little sulphur or Ethiop's mineral and bay-salt may be given internally.
The preventive means are strict attention to cleanliness both in the styes and in the animals themselves. Whenever a pig is observed to be lousy, which will quickly be perceived by his rubbing himself against the gates, trees, and walls, he must be immediately separated from his companions, or they too will become infested with lice, if they are not already so.
Parkinson is of opinion that "the cause of vermin infesting animals clearly arises, in a general way, from bad feeding, which occasions weakness of the blood; for," says he, "if an animal be ever so lousy, by giving him strong food for a few days the vermin will disappear, probably because the rich blood is poison to them." He considers that a free access to water for bathing, and also occasional exposure to heavy rain, is not only necessary to the general health of swine, but a most excellent preservative against vermin.
LEPROSY.
This disease has apparently existed in swine from the remotest periods, and Tacitus gives it as his opinion that it was because the hog was subject to leprosy that the Jews were forbidden to eat of its flesh. It consists in the development of certain vesicles, or whitish granulations, in all parts and portions of the cellular tissue; which vesicles have been proved to be neither more nor less than a species of worms termed the cysticercus cellulosa, supposed by some French authors to be of the same species as that found in the brain of sheep. There are however considerable differences between these two. The cysticercus is found in all the cellular tissues and soft parts throughout the whole of the body; in the fat, in the adipose matter, in the interstices between the muscles, in the viscera, and, in short, in every crevice into which they can insert themselves. The thigh or ham has been mentioned by some authors as the principal seat of these vesicles, but they are also found on the shoulders, around the jaws, along the neck and belly, and even underneath and around the root of the tongue, where alone can any outward lesions indicative of leprosy be in general discovered; and even here they are not constant, out are chiefly evident in those animals in which the disease has attained to a great height. The progress of leprosy is very insidious, and the early symptoms so little marked that a practised eye only can detect them.
In the onset all that is observable is a certain marked stupidity or obstinacy in the animal; a state of languor and apparent general debility; an evident thickening of the skin; a slight adhesion of the bristles; a tendency in the hair to fall off, caused by the development of a greater or less quantity of those vesicles of which we have spoken, as being scattered in different parts of the fatty tissue, either on its surface or in the interstices of the muscles; under the coats of the viscera, or on the sides of the tongue.
In its successive progress this disease attacks the animal economy more or less profoundly without the functions appearing otherwise troubled. There is ulceration of the cellular tissue, and even of the organs that surround or penetrate it: the animal does not however appear to be generally and seriously ill. Far from losing his appetite, he is occasionally extremely voracious. He does not appear to suffer in the lungs; his breath is not embarrassed, nor is his voice hoarser than usual.
Such is at least what may be observed to take place when the leprous vesicles are not numerous. It is when they increase in quantity and the disease increases that they begin to affect the health of the patient. He then becomes indifferent to every thing; moves about slowly; totters as he walks; his eyes are dull; the buccal membrane is pale, and sometimes strewed with violet spots. The expired air is fetid, the breathing slow; the pulse small and irregular, the bristles easily plucked, and sometimes a little blood accompanies them. Strength begins to abandon the patient; he can no longer sustain himself on his hind legs; the posterior part of the trunk becomes paralyzed, the body exhales an unpleasant smell; the skin is thicker, and the cellular tissue is raised in different parts, especially about the kernals of the neck. There is swelling about the roots of the hair, which often proceeds to ulceration; the skin comes off in patches; large tumors are developed; the teeth are ground convulsively together; the tongue is dark colored, hot, thickened, and covered with slime; the body swells; the animal utters feeble cries of pain, and seldom survives many hours.
This is a very obstinate disease, probably from its having usually taken so great a hold of the system before it is suspected, and numerous have been the medicaments recommended for it. Antimony, sulphur, small and repeated doses of Epsom salts, and general bleedings, seem to be the course of treatment most likely to be attended with success; and these must be aided by strict attention to diet and cleanliness; cooling wholesome food alone should be given, and water, in which barley-meal has been dissolved. Nothing of a rich or heating nature should be allowed to come within reach of the animal. As external applications, mercurial ointment may be moderately applied to the ulcerated parts, or the common mange ointment composed of sulphur and antimony.
In all probability the reason why this and many other diseases of swine have hitherto been regarded as incurable, is that men of science, educated veterinarians, have as yet given but little of their attention to these useful animals, and deemed the study of their diseases and of the means of treating them beneath their notice. Nor is the owner without his share of blame, for he too often either abandons the poor brute to its fate, or calls in the aid of the pig-butcher or some ignorant empiric.
There have been numerous opinions advanced relative to the predisposing causes of leprosy; some authors attribute it to exposure to the inclemency of the weather, insufficient food, and damp marshy localities; and urge in support of their opinion that the disease was much more prevalent and fatal when swine were turned into the woods and forests during certain periods of the year to seek their own food than it is now when they are comfortably lodged and more care devoted to their feeding. Others have attributed it to some pernicious qualities in the water which the animals drink, or in the food which is given to them; and with both these parties we are inclined to agree, and to attribute this disease in a great measure to vitiation of the blood.
The wild boar appears to be exempt from it; nor is leprosy known in America, Russia, or Spain, if we may believe the testimony of various authors and travellers.
Some have asserted it to be hereditary; but there are numerous facts on record in which some of the progeny of a perfectly healthy boar and sow have proved leprous, while a diseased sow has produced sound and healthy young.
Another question has likewise been much discussed, namely, the propriety or safety of eating the flesh of pigs that have died of this disease. These animals, however good condition they may appear to be in, are rather bloated than fat; the flesh is soft and flabby, and tasteless, and will not keep; the bacon pale in color and wanting consistency. Soup made with such flesh is white, greasy, and insipid, and has been known to produce vomiting and diarrhœa. We are not aware that there are any records of disease or other evil resulting from the eating of the flesh of leprous pigs; nevertheless it stands to reason that it cannot be wholesome, and should not be made use of, for although no immediate ill effects may follow the eating of it, we cannot tell what insidious evils such vitiated and diseased food may engender in the human frame.
MANGE.
This cutaneous affection, which was formerly attributed to want of cleanliness, or to some peculiar state of the blood, is now generally admitted to arise from the presence of certain minute insects termed acari. It is identical with the scab in sheep, and the itch in the human being, which also were supposed to arise from corruption of the blood, or acrid humor subsisting in it, or from filthiness, but which arise from this scabious insect. As far back as the twelfth century these acari scabiei were described by an Arabian physician; subsequently they were noticed and described by several German and Italian writers, and in 1812 and 1814 Herr Walz, a German veterinarian, and M. Gohier, an eminent French veterinary surgeon, found these insects in, and gave drawings of, and described those peculiar to, almost all our domesticated animals.
There is a very interesting translation from a pamphlet by Dr. Hertwig, given in the Veterinarian for 1838, in which a detailed account of the habits and history of these insects will be found.
The hog does not appear to suffer so much from mange or scab as the horse, sheep, and dog; in swine, the pustules are usually chiefly developed under the arm-pits, and on the interior of the thighs. They at first consist simply of red spots, vesicles, or pimples; but these gradually become connected together by minute burrows, or furrows existing beneath the skin, and eventually unite in the form of large scabs, which the animal, irritated by the itching, rubs into large blotchy sores.
Where the mange is recent, a tolerably strong decoction of tobacco or digitalis will often prove an efficacious wash for the diseased parts, or a solution of corrosive sublimate; but if the eruption is of long standing, and has degenerated into scabs, a solution of arsenic in the proportion of one ounce to a gallon of water, or, what is still better, sulphur and mercurial ointment in the proportion of an ounce of the former to a drachm of the latter, carefully and thoroughly rubbed into the skin, must be resorted to. A decoction of soot has also been recently discovered by an eminent French physician to be exceedingly efficacious in cases of cutaneous disorders. Two handfuls of soot are boiled during half an hour in a pint of water, the fluid is then strained off, and the lotion when cold used two or three times in the day. Creosote has also been used with success in the treatment of cutaneous eruptions. If the animal is in high condition, blood should be taken, and two or three doses of cooling physic given, or sulphur mingled with the food. Strict attention must be paid to cleanliness, and the animal kept apart from the rest of the herd. Mange is both hereditary and infectious. There are numerous instances of its having been communicated from one animal to another of a different species, and even to the human being.
In Austria, if mange appears in the hog within eight days after the sale, it is presumed to have existed at the time of the said sale, and the animal is returnable to the vendor; and when it can be proved that he was aware of the unsoundness, he not only has to return the purchase-money, but also to indemnify the purchaser for any loss or inconvenience he may have sustained, besides paying a fine equal to one-tenth of the value of the animal.
That the actual disease, namely, the scab and the irritation, arises from the presence and proceedings of the acari, there can be no shadow of doubt; but the question is, whence do these acari arise? Are they the product of some morbid state of the skin, arising from constitutional derangement, or created by miasma or effluvia? We find mange in animals that are fed on too stimulating food, we also find it in others that are neglected and badly fed. How can these contradictions be reconciled? Here is a vast field for scientific research and experiment. As every grain of earth, and every drop of water, and every particle of air, is peopled with living beings, developed by certain causes, it is by no means an improbable theory to suppose that the germs of the acari may exist in a dormant state in the skin, and only be called into actual life by some of the vitiating influences which neglect or mismanagement produces, and once existing, they follow the law of every created being, and propagate and multiply, and pass from one animal to another either by actual contact, or by the intermediation of some other substance which both had touched. We admit, however, that this is mere theory, and call upon our professional brethren to aid us by their researches in our endeavors to discover the actual truth.
MEASLES.
This is rather a sub-cutaneous than an actual disease of the skin, consisting in a multitude of small watery pustules developed between the fat and the skin, and indeed scattered throughout the cellular tissue and adipose matter. It has, by many, been regarded as a milder form of leprosy; and so far as our present limited knowledge will allow us to judge, this supposition appears by no means an erroneous one.
The external appearances attending it are the development of reddish patches, somewhat raised above the surface of the skin, on the groin, the arm-pits, and the inside of the thighs at first, and subsequently on other parts of the body. The attendant symptoms are acceleration of the pulse, heat of the skin, cough, discharge from the nostrils, loss of appetite, nausea, swelling of the eyelids, feebleness of the hinder extremities, and the formation of blackish pustules under the tongue: eventually the skin usually comes off in patches. The measles in swine is seldom fatal, and will gradually yield to the simplest cooling treatment, or even to mere attention to diet, temperature, and ventilation. Didyinus tells us that Democrates prescribed bruised asphodile roots to be mingled with the food given to hogs, as an excellent remedy for this disease. It sadly injures the quality of the meat, rendering it insipid, flabby, pale, and indisposed to take the salt. We should say that the flesh of measly pigs is positively unwholesome, although, perhaps, there are no cases on record in which it is proved that bad effects have resulted from the use of it.
The following was a remedy for this disorder used by the ancients: "A hog having measles must be put in a sty and kept there three days and nights without food. Then take five or six apples, pick out the cores and fill up the holes thus made with flour of brimstone; stop up the holes and cast in the apples to the measly hog. Give him first one or two, then one or two more, and then, as being hungry he will eat them, give him all. Let him have nothing more to eat until the next day, and then serve him so again. Thus use him for five or six days, and he will become as well and as wholesome as ever." In our opinion it is one very likely to be beneficial.
It yet remains to be discovered whether measles in swine is an epidemic, like that disorder in the human being, or whether it is hereditary, or whether, as many suppose, it arises from the development and presence of a variety of the cysticercus.
DESQUAMATION OF THE SKIN.
The following singular case, communicated to The Veterinarian, by Mr. J. Sherwood, of Sittingbourn, appears to us not unworthy of record here.
"A few weeks ago the skin became hard on either side about nine or ten inches from the spine, and afterwards kept gradually separating towards the centre of the spine from the shoulder to the insertion of the tail. The bailiff cut off portions from time to time of the weight of nearly 10 lbs. in order to make the load with which the animal was encumbered the lighter, until the last week, when the hog lay down, and after taking his rest with his brethren (for he fed and looked as well as the rest, with the exception of the load on his back) he got up and left the substance behind him. It consisted of the entire skin so far as it had sloughed, with about two inches of adeps adhering to it in the middle, getting gradually thinner towards the sides, and weighing 20 lbs., which, added to the portions before removed, made a total of 30 lbs. The hog is now computed to weigh 400 lbs. He had not any medicine administered, as he did well the whole of the time."